Apparatus for burning fuel



Feb. 18, 1,930. E H, STEEDMAN 3,747,191

' APPARMUS FOR BURNING FUEL Filed Feb. 6, 1928 /N VEA/Toe: v

Patented Feb. 18, 1930 PATENT ori-ica4 EDWIN H. STEEDMAN, OF ST. LOUIS, MISSOURI APPARATUS IOR BURNING FUEL Application nled February 6, 1928. Serial No. 252,300.

This invention relates to fuel burners of the kind in which the combustion air is supplied to the combustion chamber by a fan or other suitable means.

One object of my invention is to provide a practicable apparatus for burning a gaseous, liquid or pulverized fuel that is of durable construction, inexpensive to build and install, reliable in operation, and of such design that it will burn fuel with less noise than 1s produced by conventional burners.

Another object is to provide an apparatus for burning a gaseous, liquid, or pulverized solid fuel that insures an excess supply of combustion air when the fuel is first ignited, which excess air supply is thereafter automatically reduced, and during the continuance of the operation of burning the fuel, is maintained at the minimum quantity of air required for proper combustion.

To this end I have devised an apparatus for burning a gaseous, liquid, or ulverized solid fuel which is of such design t at fuel will be introduced into a combustion chamber or other suitable space and combustion air will be supplied to said chamber or space under pressure, -the velocity of the air that is being admitted to or introduced into the apparatus being utilized to cause additional combustion air or a gas or products of 'combustion to be drawn from said combustion chamber and incorporated with or injected into the burning fuel. By this procedure I obtain a sufficient excess supply of combustion air in the burning mixture, when the fuel is first ignited, to produce plractically smokeless combustion and also e 'minato the possibility of the fiame becoming extinguished. The excess sup ly of combustion air is Yautomatically re uced and finally replaced by hot products of combustion after the apparatus has been in operationp'for a short period thereby producing a high temperature of combustion with minimum noise or violence of combustion, and also insuring the'minimum quantity of air required for proper combustion during the continuance of the opera-A tion of burning the fuel.

My invention is apjlicable to various types and kinds of fuel urning' apparatus, in

which combustion air, orcombustion air together with fuel, is introduced into the combustion chamber under pressure, or with sufficient velocity to create a suction or partial vacuum that can be utilized to cause a volume of additional air, or gas or products of coinbustion to be incorporated with, mixed with or injected into the burning fuel. It is particularly applicable, however, to automatic oil burners of the kind that are now used extensively in domestic heating apparatus, and accordingly, l have herein illustrated it embodied in an oil burner of the kind that is equipped with a nozzle from which a stream of combustion air mixed with particles of oil 05 is discharged'under pressure into the combus- Ition chamber or space in 'which the' fuel is burned.

' Figure 1 of the drawings is a diagrammatic horizontal sectional view, illustrating one form of my invention.

Figure 2 is ra view partly` in vertical section and partly in side lelevation of the apparatus shown in Figure 1, and A Fi ure 3 is a diagrammatic horizontal sec- 75 tiona view, illustrating another form of my invention. 4

In the form of my invention illustrated in Figure 1 A designates the combustion chamber of a fuel burning apparatus, such as a 8U domestic heating furnace, B designates a supplementary combustion chamber arranged preferably beneath or at the lower end of the combustion chamber A and provided at its upper end or in its top wall l with an opening 2 that discharges upwardly into the combustion chamber A, and C esignates as an entirety any suitable type or kind of burner capable of beingused for burnin a gaseous, a liqu'id, or a pulverized 9 solid uel and provided with a nozzle 3 through which a stream of combustion air, or air, together with fuel, is' introduced under pressure, or at considerable velocity into the supplementary combustion chamber B. As is usual, the burner C is equipped with a fan (not shown) that is driven by an electric motor 4 or other suitable source of power. The sup lementary combustion chamber B can be ormed of metal or refractory material;

it can be of various forms and dimensions and it can be arranged in various ways with 1 having an opening 2, as previous y described. The nozzle 3 of the burner C projects inwardly through an opening in a part 5 of the front wall of the furnace, and the terminal portion 3a of said nozzle is tapered or made substantially cone-shaped, so that it will co-operate with a flared or tapered opening 6 in the side wall of theI supplementary combustion chamber B to form an annular restricted passageway inwhich a suction or partial vacuum is created by the velocity of the stream of combustion air or air and fuel emer ingl from the nozzle 3 of the burner C, there y causing additional air or gas or products of combustion to be sucked from the combustion chamber A into said restricted passageway and incorporated with, mixed with or injected into, the burning mixture in the supplementary combustion chamber B. The volume of the air, gas or productsof combustion taken from the main combustion chamber and injected into the burning mixture can be accurately controlled or regu lated in various ways, as, for example, by

-varying the size or shape of the inlet 6 in los the side wall of the supplementary combustion chamber, or by changing the relationship or distance between the tapered portion 3 of the nozzle 3 and the edge of the flared or tapered orifice 6 which surrounds the same.

While I have stated that the terminal portion of the nozzle of the burner co-operates with an opening in the side wall of the supplementary combustion chamber to form 1n effect an injector, by means of which a volume of combustion air or gas or products of combustion is injected into the burning fuel, I wish it to be understood that the particular form or design of the injector that is used is immaterial, the essential thing being that the device which is used to supply or 1ntroduce a stream of combustion air, or air and fuel, into the fuel burning apparatus, be located inthe main combustion chamber and of such a character -that the force or velocity of the incoming stream is utilized to cause additional air, or a mixture of air-and products of combustion in the combustion chamber, to

' be added to andefectively mixed with the burning fuel.

It is immaterial whether the stream of combustion air, or air and fuel, is introduced into the supplementa combustion chamber, or

into the main com ustion chamber ofthe ap-l paratus. Accordingly, in Figure 3 of the.

drawing I have illustrated an apparatus embodying my invention, wherein the nozzle 3 of the burner C projects directly.into,the4

main combustion chamber A of theapparatus, and the terminal ortion of said nozzle is associated with a ared or tapered `annular member 6 that co-operates with said terminal portion, to form in effect an injector which causes air, gas or products of combustion to be sucked from the combustion chamber A and injected into the fuel that is being burned in said combustion chamber.

The principle of operation of the two forms of my invention above described is the same. When the burner is first started or set in operation, the interior of the combustion chamberA is filled with relatively cold atmospheric air unmixed with products of combustion, and gradually, as the operation of burning the fuel proceeds, the interior of the combustion chamber A becomes filled with hot products of combustion containing some atmospheric air. Gradually, from the time. the burner is started, the total amount of air for combustion is reduced by the addition of products of combustion, which are injected into the burning fuel, thereby causing the temperature of combustion to be increased and the rate of combustion slowed down, on account of the dilution of the burning mixture with products of combustion. After the burner has been in operation for a comparatively short time, the amount of air available for combustion becomes practically constant.

Inmy improved apparatus there is suflicient excess oxygen present when the fuel is ignited to eliminate the possibility of the flame becoming extinguished, but the excess .100 supply of combustion airis gradually ycut down and finally replaced by hot products of combustion which are injected into the burning fuel, thereby producing a high temperature of combustion that results in economy of., 105

fuel, and also reducing the violence of comliquid or plulverized solid fuel, comprislng a main com ustion chamber, a supplementary combustionchamber arranged at .the lower end of said main combustion chamber and provided with a substantially circular side .120

wall, an opening in the top of said supplementary combusti/on chamber through which the ame is discharged upwardly into the main combustion chamber, a nozzle whose terminal portion is.v tapered' or substantially l'conel shaped, and a flared or tapered .opening .in thee'side 'wall of said supplementary'combustion chamber lcombined with the terminal portion of said nozzle so as to form an apnular.restrictedI passageway-hnlich.suction m is created by the velocity of the stream emerging from ie nozzle, thereby causin additional air, or gas, or products of com ustion to be sucked from the main combustion chamber and incorporated with, mixed with or injected into the burningmixture in the supplementary combustion chamber.

2. An apparatus forz burning a gaseous, liquid or ulverized solid fuel, comprising a main com ustion chamber, a supplementary combustion chamber arranged at the lower end of said main combustion chamber and constructed so that the flame in the supplementary combustion chamber will be discharged upwardly into the main combustion chamber, a nozzle for introducing a stream of air into the supplementary combustion chamn ber provided witha tapered terminal portion, and an opening in one Wall of the supg@ plementary combustion chamber that co-acts with the terminal portion of said nozzle to form an injector which causes additional air, gases or products of combustion to be sucked from the main combustion chamber and in- 2,5 corporated with, mixed with, or injected into the burning fuel in the supplementary combustion chamber.

3. An apparatus for burning a gaseous, liquid or ulverized fuel, comprising a combustion e amber, a nozzle through which a gaseous stream is introduced into said combustion chamber under pressure, provlded with a tapered ortion that is positioned in. side of said com ustion chamber, and a tubular member in the combustion chamber completely surroundin the tapered terminal ortion of said nozz e and spaced away thereirom sogas to form an injector having an annular passage through which air, gases or products'of combustion in the combustion chamber will be drawn and incorporated with, mixed with or injected into the burning fuel in the combustion chamber.

EDWIN H. STEEDMAN. 

